On Mon, Aug 17, 2009 at 04:20:24AM +0200, Herbert Poetzl wrote: > looking at the i8259 implementation found in qemu > as well as in the in-kernel kvm implementation, I > see that on pic_reset() special_fully_nested_mode > is set to zero, but the intel(r) 8259A manual says > on page 15: > > Fully Nested Mode > > This mode is entered after initialization unless > another mode is programmed. > > any comments are appreciated, You confuse two modes of the PIC: the FullyNestedMode and the SpecialFullyNestedMode. See page 18 in the manual. The first ist the "default" mode, where an IRQ in service from a slave masks further interrupts from this slave. In SFNM a slave PIC can still issue another IRQ. Greetings, Bernhard Kauer -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html